This invention relates to a break open firearm that has a top lever adjusting system and preferably an automatic ejection system, an automatic safety system and a fore-end tension adjusting system.
Break open firearms, and particularly over and under shotguns in which the barrels are alligned vertically in the firing position, have long been known. However, several features have been subject to continuing development.
The ejection system, for removing spent shells from the firearm, desireably should be easily converted between automatic and manual, to accomodate shooters who save their fired shells for reloading.
Further, adjusting systems are needed to allow the radial positioning of the centerline of the top lever just to the right of the centerline of the frame top tang when the action is closed. Specifically, a top lever adjusting system would be desireable that allows the radial position of the centerline of the top lever to be easily positioned just to the right of the centerline of the frame top tang when the action is closed. This would ensure that as wear occurs to the firearm's locking system, the top lever centerline would gradually move to be inline with the centerline of the top tang. A gun which has its top lever centerline to the left of the top tang centerline is generally considered to be "worn-out," although this might not necessarily be the case. A further requirement is that the top lever always be in a position to latch itself open at approximately the same time as the barrel assembly is released to be pivoted open.
Still another desireable feature of such firearms would be an automatic safety system that can be easily converted to a manual safety, combined with a safety/barrel selector mechanism that could also be locked in the fire position to always fire a preselected barrel first. A large number of modern over and under shotguns incorporate a safety switch that is automatically returned to the "safe" position each time the top lever is operated to break the gun open for reloading or unloading. This requires that the safety switch be pushed to the fire position before the gun can again be fired. Many competitive target shooters do not like this automatic safety system and will have it converted to a manual safety system, such that as soon as the gun is reloaded it can be fired without having to operate the safety switch.
All shotguns that incorporate automatic safeties can have them modified to manual safeties. This procedure is somewhat involved, requiring that parts be permanently removed from the safety mechanism by a competent gunsmith. Currently available shotguns cannot have the safety mechanism modified easily by the owner.
A further need for break open shotguns is a fore-end assembly tension adjusting system that allows barrel interchangeability with no change in fore-end assembly tension. It is considered desirable on modem shotguns that the fore-end iron radius should be a tight fit against the mating radius of the frame, such that it produces a slight drag to prevent the barrel assembly from flopping down when the top lever is rotated to open the gun. The majority of shotgun manufacturers accomplish this by hand fitting the rear surface of the barrel lug such that there is no clearance between it and its mating surface on the fore-end iron, as well as between the mating radii of the frame and fore-end iron and between the frame trunnions (pivot pins) and their mating half radius cuts in the barrel mono-block. This is a time consuming operation requiring a high degree of skill.
Over time these surfaces will wear, especially the trunnion and mono-block surfaces which are subjected to the full gun recoil forces. This eventually leads to loose fitting parts. These potential problems have previously been handled by providing a screw type adjustment device in the fore-end iron. This solution has worked well except in those cases where a gun has been equipped with more than one barrel assembly, which is common in the over and under shotgun market. This has required that the fore-end iron be disassembled from the fore-end so that adjustments can be made to suit each individual barrel assembly.